The present invention relates to the manufacture of concrete walls used in tilt-up construction. More particularly, the present invention is directed to a spacer/support that holds a weldment plate in proper position until the wet concrete sets up.
In commercial construction, as well as in residential construction where wood is at a premium, builders are increasingly using tilt-up construction, that is, they are pouring concrete walls in forms as they lay on the ground, floor or other surface, and then tilting them up into the desired position after the concrete has cured. One of the features such construction affords is the placement of a weldment plate on one surface of the wall so that structural support beams, and the like, may be welded/secured between adjacent walls. In current practice, the concrete wall is poured and then the weldment plate is xe2x80x9cfloatedxe2x80x9d on the top of the wet cement. Since these Steel plates are denser than the wet concrete, they tend to sink below the surface. Accordingly, it sometimes becomes necessary to allow the concrete to take a partial set and then attempt to push the weldment plate into the desired position. Neither of these current practices provides effective quality control and the results often are not those desired.
The device of the present invention comprises a spacer/support that engages the support surface on which the concrete wall is poured and a weldment plate holding it in the desired position relative to that surface during the curing of the concrete. The spacer/support comprises a elongate body portion having a length substantially equal to the thickness of the concrete wall minus a dimension of the weldment extending in the direction of the thickness of the concrete wall; a surface engaging portion for contacting the surface on which the concrete wall is poured and supporting the weldment in a position appropriately spaced from that surface; means for attaching said body portion to the weldment; whereby the weldment will be maintained in a desired position as wet concrete is poured and sets up.
Weldment plates take different forms: some are simply rectangular metal plates with two smooth surfaces. Other weldment plates are equipped with protrusions on one surface that improve the adhesion of the plate to the wall enabling greater weight to be suspended therefrom. These protrusions typically take the form of a plurality of Nelson studs welded to the surface of the plate that is to be embedded in the concrete. These studs can have shaft diameters of xc2xcxe2x80x3, xe2x85x9cxe2x80x3, xc2xdxe2x80x3, ⅝xe2x80x3 with head diameters graduated by xc2xc increments between xc2xdxe2x80x3 and 1xc2xcxe2x80x3. For weldment plates that have no protrusions, the support/spacer will have additional length (as compared to those engaging the heads of Nelson studs) and be equipped with a flat head that can be adhered to the nether surface of the weldment plate by an adhesive such as LIQUID NAILS (a registered trademark of Macco). A minimum of three spacer/supports will be used on each weldment plate positioned in a triangular pattern to provide balance in the wet concrete. The embodiment of support/spacer engaging the Nelson stud will have a plurality (three shown) of fingers that grip the head of the stud, the fingers having portions that snap beneath the head and retain the spacer/support in position while the concrete sets up. This configuration will be made in a plurality of sizes to accommodate the various sizes of Nelson stud heads.
The spacer/support is preferably made of a material selected from the group consisting of plastic, metal, and powdered metal. The end contacting the support is preferably pointed to minimize the surface treatment needed for the wall and, typically, the wall may simply be painted, papered or given any other conventional treatment, without the tips of the spacer/supports affecting the treatment. The length of the body portion of the spacer/support may be adjusted in either of two ways: the surface may be scored at any of a plurality of conventional lengths, and the spacer/support cut to the length appropriate for the wall thickness with which it is used; the spacer/support includes two parts that may be adjusted relative to each other to achieve the desired length. Preferably, these pieces are threadingly engaged and the length can be readily adjusted by rotating one of the pieces relative to the other. This feature may be added to either the flat-head or fingered configurations.
Various other features, advantages and characteristics of the present invention will become apparent to one of ordinary skill in the art after a reading of the following specification.